Awning
SashA frame in which the panes of a window are
set. The frame is built in such a way that the bottom swings outward in a window
frame.

Awning Window
UnitA combination of a frame, one or more awning
sashes, weather-strip and an operating device assembled as a complete and properly operating unit;
screens and/or storm sash are optional; the unit may contain one or more fixed or non-operative
sashes in combination with the operative sash.

Bay
WindowA bay window is made up of three or more
windows. The side or flanker units project out from the building in 30, 45, or 90 degree angles.
The center is parallel with building wall and is made up of one or more windows. All the units can
be stationary, operating, or any combination thereof.

Bifold
DoorA segmented, hinged door that folds into
itself and slides on a head track to the side when opened. A typical 4-0, 5-0, or 6-0 door is made
up of four door segments: two folding to the right and two to the left. This door was first used
during the 19th century. Bottom RailA horizontal rail at the bottom of a sash, door, blind or other panel
assembly.

ButtA door hinge with one leaf mortised or routed into the door frame jamb
and the other into the edge of the door. The leaf of the hinge can be radiused or square. A
standard residential interior hinge measures 3 1/2 x 3 1/2 inches when laid out flat. A standard
residential exterior hinge will measure 4 x 4 or 4 1/2 x 4 1/2 inches.

Casement
WindowA window in which the frame is built in such
a way that the sash can open out like a door when installed in a window unit. Historically,
casements were the first working windows. These windows were strategically placed throughout a
house to capture breezes and direct them through the rooms. Screens were placed internally to
prevent bugs and dirt from entering the house.

CasingMolded or surfaced four-sided wood pieces of various widths and
thicknesses, used for trimming door and window openings. A casing may be classified as exterior or
interior as far as window and exterior door frames are concerned.

Check
RailIn double-hung windows, this is the bottom
rail of the upper sash and the upper rail of the lower sash, where the lock is mounted. It is also
know as a Meeting Rail.

Combination
DoorA door that is made with a wood panel as the
bottom half and a screen for ventilation as the top half. Also called a ventilating
door.

Composition Door
PanelA door panel of a material other than solid
wood or plywood.

CondensationMoisture or humidity in the air that forms on a cool surface such as a
pane of glass. When moist air comes in contact with a cool surface it shrinks. If it shrinks enough
to reach 100% humidity or the dew point, moisture will form on the cool surface. This is
demonstrated when the out side of a glass of ice tea sweats. CoreThe center of plywood or
crossbanded construction; it may consist of lumber (solid or glued), particle board or veneer. Also
core unit; innermost layer in veneered door construction.

Decorative Entry
SystemAn entryway made up of a door in a frame,
one or two sidelights, and a transom.

DelaminationA separation of piles or layers of wood through failure of the
adhesive.

DensityThe weight of a substance per unit volume; for example, 23 lbs. per
cubic foot.

Dimensional
StabilityThe ability of a material to stay put or
to resist changes in its dimensions due to temperature, moisture or physical stress variations;
stability of a material.

DoorA millwork assembly of stiles, rails, and panels that swings, slides,
tilts up or folds in order to close an opening in a wall or cabinet. A modern door may be used on
the exterior or interior, and may be either flush or panel type. Historically, there were two types
of doors: ledge and brace (or batten) and paneled doors. An exterior door used before the 17th
century, the ledge and brace style was constructed from vertical panels that were held together
with a Z-shaped brace nailed to the back. A Tudor-style door is similar to the ledge and brace
except that it is held together by oak planks across the back instead of a Z-brace. In the 1600's,
the paneled door came into use as an interior door. The first examples were made with two or four
panels, but then near the end of the 18th Century, a six-paneled version was made, called a
Georgian door.

Door
CasingSame as casing; may be an interior or
exterior door casing; exterior door casings are installed only on the outside of exterior door
frames, especially on wood facing wood-frame exterior walls.

Door
FrameA group of wood parts machined and assembled
to form an enclosure and support for a door; door frames are classified either as exterior or
interior door frames.

Door
JambThe part of a door frame that surrounds and
contacts the edges of the stiles and the top rail of a door. Jambs may be classified as head or
side jambs and as plain or rabbeted.

Door
PanelA sheet of thin lumber, plywood or
composition material inserted into the frame formed by the stiles, rails and mullions of a
door.

Door
TrimThe moldings required to finish or trim the
side of a door frame, consisting of two pieces of side and one of head
casing.

Double-GlazingTwo panes of glass
separated by an air space; double glazing may be accomplished by storm sash or insulating glass;
this term sometimes refers to storm sash.

Double-Hung
WindowTwo sashes, top and bottom, that slide
vertically past each other, joined by a meeting rail and held in any open position by means of
weights or one of several types of balancing devices.

Dovetail
JointA joint formed by inserting a projecting
wedge-shaped member into a correspondingly shaped cutout member.

EntranceAn exterior door frame with or without transom or sidelight (usually
used for the main or front entrance of a structure) with decorative exterior trim; trim may include
pilasters, entrance head or cap or a decorative exterior casing.

Entrance
DoorA door on the front or main entrance of a
structure; may be single or paired.

Exterior
CasingA casing that trims the exterior of a window
or door frame and serves as the boundary molding for the siding material; forms a rabbet with the
blind stop or a jamb for the screen.

FabricatorThe person or firm that assembles all the component parts into a
complete window, door or sash unit.

FenestrationThe placement (or arrangement) and sizing of the windows and exterior
doors of a building. In Greek architecture, windows began as simple openings in temples. These
openings began to contain glass in the 13th century, when clear glass was available for buildings
such as Westminster Abbey. Another important shift in fenestration occurred in the 20th century
when large windows became important components in commercial buildings.

FingerjointA series of fingers machined on the ends of two pieces to be joined,
which mesh together and are held firmly in position by a water-resistant
adhesive.

FinishThe interior or exterior finish of a structure; the finished or actual
size of a piece of lumber; the protective coating given a wood member; upper or select grades of
softwood lumber.

FixedRefers to windows that are non-venting or
inoperable.

Flat Door
PanelA door panel consisting of a flat piece of
plywood, solid wood or other material in contrast to a raised door panel.

Flush
DoorA door consisting of a core, cross-banding and
flat-face veneers, or a door consisting of a core and flat-face veneers
only.

French
DoorAn interior or exterior door consisting of
stiles, top and bottom rail and divided glass panels or lights; often used in pairs as a casement
or terrace door. In the 19th century, glass was being added to door construction, mainly in French
and German homes, on internal doors leading to rooms containing more natural light, such as
conservatories, glass houses and vestibules.

French Casement
WindowTwo casement sashes, each hinged on one
stile and opening in the middle but with no center mullion. This allows a smaller rough opening to
make egress since there is a large unobstructed opening.

Garden
WindowA box-shaped window that hangs outside the
house and can be used as a greenhouse for plants. It has a slanted glass roof that pulls in heat
and light from the sun.

GlazingThe insertion of glass into sashes and doors. Glazing also refers to
the lowest quality of plate glass. The purpose of glazing is to retain the glass adequately under
the design load, provide effective weathering sealing, prevent loads or pressure points on the
glass resulting from building movement, prevent glass-to-metal contact, and minimize glass breakage
from mechanical or thermal stress.

GrainAn arrangement and direction of alignment for wood elements or fibers;
can be straight or spiral grain; also used loosely to indicate texture.

HandA term describing the swinging direction of a door as one stands on
the side of the door from which security is desired, namely the outside.

HardwoodOne of the botanical groups of trees that has broad leaves in contrast
to the needle-like leaves of the conifers or softwoods; hardwoods are deciduous (they shed their
leaves in the fall or at the end of each growing season).

HingeA jointed or flexible device on which a door or window turns. The
earliest known hinges were T-shaped devices called strap or cross-garnet hinges. They were made of
wrought iron with a cross bar fixed vertically to the door frame, and attached with nails to the
door. In the 18th century, hinges for interior doors were H-shaped or L-shaped, and attached to the
door with nails.

Hollow-Core Flush
DoorA flush door with a core assembly of strips or
other units of wood, wood derivative or insulation board, that supports the outer faces and has
intervening hollow cells or spaces.

Horizontal
LightA light or cut-out formed by a horizontal bar
extending from stile to stile of a sash or door.

KickplateA thin, polished metal plate applied to the bottom rail or bottom of a
door to prevent denting and soiling of the wood surface caused by the kicking action of persons
opening the door; kickplates may be applied to one or both sides of a
door.

Kick
RailA rail located approximately 10 to 12 inches
from the bottom of a hollow-core flush door frame, used primarily on institutional
doors.

Kiln-DriedAnything that is wood
seasoned in a kiln by means of artificial heat, humidity and circulation; kiln-dried wood may refer
to wood with various moisture content percentages.

KnotA branch or limb embedded in a tree and cut through during lumber
manufacturing; the size of a knot is determined by averaging its maximum length and width of the
knot.

MouldingA relatively narrow strip of wood, usually shaped to a curved profile
throughout its length; used to accent and emphasize the ornamentation of a structure and to conceal
surface or angle joints.

MullionA wood or metal part used to structurally join two window or door
units.

PanelA wood surface within a surrounding frame. All panels have structural
frames, the interstices of which are filled with sheets or fields called
panels.

Panel
DoorA door constructed with panels, stiles, and
rails on a wood surface. Combining several smaller components (stiles, rails, loose-fitting panels)
into one door allows panel doors to maintain their shape while expanding and contracting with
weather and temperature changes. This door style was first developed in the eighteenth century as
an alternative to batten doors, which didn't function well under moisture and climate
changes.

Passage
DoorAn interior door connecting two inside rooms
or used for a closet door; this door type does not have the same strength, insulation or security
requirements of an exterior door. Panel construction on passage doors is designed to allow the wood
to expand and contract with changes in moisture and temperature; the center panels are allowed to
float within the door's frame.

Patio
DoorA door that opens onto a patio, deck or
backyard of a house, usually made of glass to allow for viewing. Originally homeowners asked for
glass doors from a glazer, or someone who handles glass. This specialty product was created by
distributors in small shops. In the 1960s when aluminum sliding doors became very popular, window
manufacturers realized they could make patio doors to fill the openings that used to be filled by
solid doors. At that point, the window companies started heavily promoting patio doors, made in
aluminum, vinyl and wood. Door companies now also make them in wood, composites and steel. The same
as a stationary or fixed sash, a picture sash or window usually implies a relatively large-sized
sash.

Prehung Door
UnitA precut and assembled unit consisting of a
door with the locking or passage hardware hung on hinges in a wood frame.

Prime
CoatThe first coat of paint in an application that
consists of two or more coats.

SashA single assembly of stiles and rails in a frame for holding glass,
with or without dividing bars or muntins, to fill a given opening; it may be either open or
glazed.

Sash
CordThe rope or chain attaching the sash to the
counter balance in a double-hung window.

Sash
DoorA door that is constructed with the bottom
half made up of a wood panel and the top half made of glass to allow for a
view.

Sash
LiftA handle built into the bottom rail of the
lower sash on a double-hung window.

Sash
WeightThe concealed cast-iron weight used to
counterbalance the sash in double-hung windows.

Screen
DoorA door that is made with a wood panel as the
bottom half and a screen for ventilation as the top half. Also called a ventilating door or
combination door.

ShuttersA wood assembly of stiles and rails to form a frame that encloses
panels used in conjunction with door and window frames; may also consist of vertical boards cleated
together. Shutters have been around since windows were first used. By the 16th century, interior
paired shutters were used throughout Europe, often stacked in two or four tiers. By the late 18th
century, interior shutters were made with louvered and solid panels.

SidelightAn assembly of stiles and rails, with or without a wood panel,
containing a single row of glass panels or lights and installed on one or both sides of an exterior
door frame, especially a front entrance door frame. Also used in older houses to frame interior
doors.

SillA main horizontal member forming the bottom of the frame of a window
or door.

Single
GlazingThe use of single panes of glass in a
window.

Single-Hung
WindowSimilar to a double-hung window with the top
sash stationary or inoperative while the bottom sash operates freely; also, a vertical
slider.

SkylightA window installed in a roof and assuming the same slope. Depending on
which direction they face, skylights can bring in more light and heat than windows. For example, in
the summer months, an unshaded south-facing skylight will bring in more direct sunlight and heat
than a window. In a cold climate, a north-facing skylight gives almost five times more light than a
north-facing window with almost the same amount of heat loss.

SoftwoodOne of the botanical groups of trees that has persistent needle-like
or scale-like leaves; softwoods are evergreen and have longer-length fibers than
hardwoods.

Solid-Core Flush
DoorA flush door consisting of a core of solid
wood blocks or strips with cross-banding and face veneers, or with face veneers
only.

Solid Door
PanelBeveled on one or two
sides.

Stationary
SashA fixed or inoperative sash, often used in
combination with other types of window and sash units; intended primarily for viewing purposes and
for admitting light.

StileThe uprights or vertical outside pieces of a sash, door, blind or
screen.

Stop
BeadA molding used to hold, position or separate
window parts.

Swinging Patio
DoorA patio door of two or three sections, one of
which swings inward or outward like a regular door, with the other sections
fixed.

Tilt
WindowA double-hung window designed in such a way
that the sashes tilt inward for easy cleaning of the outside of the glass.

Tongue and Groove
JointA joint formed by the insertion of the tongue
of one wood member into the groove of the other; modifications include tongue and groove rabbet
joint, dado tongue and rabbet, tongued shoulder joint, dado and rabbet joint, dado and rabbet
joint, dado and lip joint.

Top
RailThe top rail of a sash, door, blind or other
similar panel assembly.

TransomA small opening above a door or window separated by a horizontal
member that usually contains a sash or a louver panel hinged to the transom bar. Transoms, or fan
lights, were first used in the 18th century on exterior doors. They increased the amount of light
let into the front hall, and because of them, the size of the front door could be reduced. They
probably encouraged the Victorian use of stained glass for front doors.

WarpAny distortion in the plane
of a door itself and not in its relationship to the frame or jamb into which it is
hung.

WeatherstripVariously shaped
metal, vinyl, plastic or molded fiber strips that fit tightly against the sash or door frame parts
to prevent air infiltration through cracks. Cold air entering the house in winter can account for
up to 35% of the heating load. Weatherstripping can reduce the load to
20%.

Window
CasingMay be interior or exterior; an exterior
window casing is most commonly installed on window frames for wood facing wood frame exterior
walls; along with the blind stop, it forms the rabbet for the storm sash or
screen.

Window
FrameA group of wood parts machined and assembled
to form an enclosure and support for a window or sash.

Window
JambThe part of the window frame that surrounds
and contacts the window or sash that the frame is intended to support.

WindowsA wall opening in a building added for the purpose of letting in light
and air, usually sealed from the elements in some way, using a frame and sash containing glass or
another type of transparent material, and usually able to be opened and shut. Windows containing
glass began being heavily used in the late nineteenth century with advances in glass technology and
frame construction. Windows gave building occupants options about views, ventilation, and exterior
design.